The diseases or groups of diseases described generally as helminthiasis are due to infection of the animal with parasitic worms known as helminths. Helminthiasis and helminthosis are prevalent and may lead to serious economic problems in sheep, swine, cattle, goats, dogs, cats, horses, poultry and man. Among the helminths, the groups of worms known as nematodes, trematodes and cestodes cause widespread and often-times serious infections in various species of animals including man. The most common genera of nematodes and cestodes infecting the animals refered to above are Dictyocaulus, Haemonchus, Trichostrongylus, Ostertagia, Nematodirus, Cooperia, Bunostomum, Oesophagostomum, Chabertia, Strongyloides, Trichuris, Fasciola, Dicrocoelium, Enterobius, Ascaris, Toxascaris, Toxocara, Ascaridia, Capillaria, Heterakis, Ancylostoma, Uncinaria, Onchocerca, Taenia, Moniezia, Dipylidium, Metastrongylus, Macracanthorhynchus, Hyostrongylus, and Strongylus. Some of these genera attack primarily the intestinal tract while others, inhabit the stomach, lungs, liver and subcutaneous tissues. The parasitic infections causing helminthiasis and helminthosis lead to anemia, malnutrition, weakness, weight loss, unthriftiness, severe damage to the gastrointestinal tract wall and, if left to run their course, may result in death of the infected animals.
The anthelmintic activity of pyridinyl acylhydrazones has not been previously reported.